<template>
  <input type="text" v-model.lazy="len" />

  <hr />

  <div class="box"></div>
</template>

<script setup>
import { ref } from 'vue'
const len = ref(300)
</script>

<style scoped>
.box {
  width: v-bind(len + 'px');
  height: v-bind(len + 'px');
  background-color: #ff00ff;

  transition: all 0.5s cubic-bezier(0.12, 1.08, 0.87, 1.6);
}
</style>
